Tehran: Iran stands "ready for useful and positive talks" on its nuclear programme as long as they are held on the basis of "equality and respect," the country's foreign ministry said on Thursday.

The comment, by spokesman Ramin Mehmanparast to Iran's Arabic channel Al-Alam, came after the UN nuclear watchdog released a tough new report saying it had evidence Iran appeared to be pursuing atomic weapons.

While President Mahmoud Ahmadinejad had earlier reacted on a more defiant tone, saying Iran "will not budge an iota" on its nuclear programme, Mehmanparast reiterated Tehran's longstanding offer to engage in talks.

"We have always announced that we are ready for useful and positive talks," he was quoted as saying.

"However, as we have repeatedly indicated, the only condition that would ensure the talks' success is that we enter negotiations with a stance of equality and respect for nations' rights," he said.

EU foreign policy chief Catherine Ashton last month wrote to Iranian officials urging a resumption of talks on the nuclear programme that have stalled since the beginning of the year.

Iran had already responded saying it was always willing to negotiate on issues of "common ground."

The talks had hit an impasse after Tehran insisted that they also include the issues of broader nuclear disarmament in the Middle East and economic cooperation.

Mehmanparast's renewed offer to restart the negotiations came after the International Atomic Energy Agency said in a report on Wednesday it had "credible" evidence that seemed to indicate Iran was trying to build nuclear warheads for its medium-range missiles.

Ahmadinejad and other officials rejected the report as biased and false, and they repeated Iran's nuclear programme was exclusively for peaceful ends.